MN10300: Generalise kernel debugger kernel halt, reboot or power off hook

Generalise the kernel debugger hook for notification of halt, reboot or power
off.  This is used by gdbstub to tell the debugger it is exiting.  This will be
useful for KGDB too.
Signed-off-by: David Howells <dhowells@redhat.com>

arch/mn10300/kernel/process.c

@@ -135,7 +135,7 @@ void release_segments(struct mm_struct *mm)
 
 void machine_restart(char *cmd)
 {
-#ifdef CONFIG_GDBSTUB
+#ifdef CONFIG_KERNEL_DEBUGGER
 	gdbstub_exit(0);
 #endif
 
@@ -148,14 +148,14 @@ void machine_restart(char *cmd)
 
 void machine_halt(void)
 {
-#ifdef CONFIG_GDBSTUB
+#ifdef CONFIG_KERNEL_DEBUGGER
 	gdbstub_exit(0);
 #endif
 }
 
 void machine_power_off(void)
 {
-#ifdef CONFIG_GDBSTUB
+#ifdef CONFIG_KERNEL_DEBUGGER
 	gdbstub_exit(0);
 #endif
 }